Tusks that were seized by the Customs and Excise Department in Hong Kong.

HONG KONG — Customs officials in Hong Kong on Friday announced one of the largest seizures of smuggled ivory ever made in the city — and their fifth since October — highlighting the pervasiveness of a trade that conservationists describe as an all-out crisis for elephant populations in Africa.

The shipment, consisting of 1,148 tusks weighing in at 2,183 kilograms, about 4,800 pounds, was worth an estimated $2.25 million, according to a customs department statement.The tusks were concealed in a container coming from the West African nation of Togo.Rising affluence in Asia has caused demand for ivory and many other wildlife products to soar in recent years, putting many animal and plant species under severe pressure.

Despite rising awareness and warnings that poaching has pushed some species to the brink of extinction, enforcement and penalties often remain weak, and represent an insufficient deterrent to poachers and smugglers, wildlife experts say.

In the case of ivory, the demand stems mainly from China, where it is highly prized for its use in ornaments and sells for hundreds of American dollars per kilogram on the black market.

Tens of thousands of elephants have been killed for their tusks in recent years in Africa, where the revenues from the poached ivory are believed to be fueling conflicts across the continent.

The fact that the number of large-scale shipments has been on the increase also is indicative of organized criminal involvement, say experts at Traffic, a group that monitors the trade in endangered wildlife.

Two other seizures made in Hong Kong in the past nine months weighed in at just over nearly 2,900 pounds, while a shipment intercepted last October weighed more than 8,300 pounds. All originated in Africa.

Hong Kong, Malaysia, Vietnam and the Philippines are the main transit points within Asia for large ivory consignments arriving from Africa, Richard Thomas, a spokesman for Traffic, said in an e-mail on Friday.